Switching apparatus



March 6, 1951 G. J. KENNEDY 2,544,535

swITcHING APPARATUS Filed June ll, 1947 4 Sheets-Sheet l y FVG. .9.

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wwf-M March 6, 1951 Filed June ll, 1947 G. J. KENNEDY SWITCHINGAPPARATUS 4 Sheets-Sheet 4 INVENTOR. q/Laffr 1Km/)foy Patented Mar. 6,1951 SWIT CHING APPARATUS Gilbert J. Kennedy, Philadelphia, Pa.,assignor to Philco Corporation, Philadelphia, Pa., a corporation ofPennsylvania Application June 11, 1947, Serial No. 754,013

(Cl. ZOO-16) 7 Claims. 1

This invention relates to circuit selector switches and moreparticularly to push-,button station selector switches for use in radiosof the multiple circuit type.

The principal object of the invention is to provide improved means forselecting one of a plurality of circuits, and more particularly one of aplurality of pretuned circuits of a radio or similar device.

Another object of the invention is to provide a switch mechanism whichis operable to select one only of a plurality of circuits, regardless ofwhether more than one selector key or pushbutton is operatedsimultaneously.

Still another important object of the invention resides in theparticular construction and arrangement of the various physicalcomponents of the mechanism, by virtue of which assembly and repair ofthe apparatus is facilitated and a considerable cost reduction iseffected.

The manner in which the aforesaid and other objects are attained, willbecome apparent from the following specification and the accompanyingdrawings illustrating a preferred embodiment of the invention, and inwhich:

Figure 1 is a general view, in perspective, of apparatus incorporatingthe present invention;

Figure 2 is a bottom plan view of a preferred embodiment of the switchmechanism of the invention, illustrated as removed from its housing andwith certain parts broken away more clearly to illustrate the variousphysical components thereof;

Figure 3 is a sectional View taken substantially along line 3-3 ofFigure 2;

Figure 4 is a sectional View taken substantially along line 4--4 of Fig.2;

Figure 5 is a fragmentary bottom plan view, with parts broken away andwith one of the selector switches shown in its operative position;

Figure 6 is a rear elevational view of the mechanism;

Figure 'l is an exploded view, in perspective, of a portion of theswitch mechanism, showing more clearly the details and interrelation ofvarious elements thereof;

Figure 8 is a perspective View of an element of the invention; and

Figure 9 is a diagrammatic view of the switching means of the invention,shown in association with an exemplary control circuit.

Referring now in detail to the drawings, and more particularly to Figure1 thereof, there is shown a casing or housing IIJ in which is housedselector switch mechanism embodying the present invention. Disposed onthe front wall of the housing are various control elements, which, inthe particular embodiment shown, comprise a plurality of push-buttonsII, a conventional On-Off volume control element I2, and a manual tuningknob I3. Neither the element i2 nor the manual tuning mechanismcontrolled by knob I3 forms a part of the present invention and,thereforey detailed illustration and description of these elements arenot necessary herein.

Referring now to Figures 2 through 6, in which the switch mechanism isshown removed from housing I, the numeral I4 designates a base memberwhich, as seen more clearly in Figure 7, is provided with a plurality ofsuitable recesses, indicated generally by the numeral I5, adapted toreceive various components of the device. The mechanism, as seen inFigure 2, comprises a plurality of switches I6, II, I8, i9, 20 and 2iwhich, as shown in Figure 9, are adapted to close associated circuitsincluding branches ISa, Ila, IBa, I9a, 20a and 2Ia, respectively, andeach of which circuits, as shown in this, the preferred form, operatesthe selector mechanism (so labeled on Figure 9) to effect selection ofone of a plurality of conventional pretuned station cirsuits indicateddiagrammatically by the block so labeled.

It should be understood, that, although the invention has beenillustrated with one type of circuit means, seen in Figure 9, in itsprimary aspect the invention is concerned with physical features of theswitch mechanism (as illustrated in Figures 1 through 8) and not withthe particular circuit arrangement shown, which may take other forms.

To facilitate further understanding of the invention, the descriptionimmediately following will have reference to switch I6 only. Referringt0 Figure 3, it is seen that this switch includes a switch key 22mounted for reciprocatory movement in a recess or guide-Way 23, formedin base member I4, the key 22 being normally urged to a projectedposition relative to base I4 (as illustrated in Figure 3) by a coilspring 24 positioned beneath the switch key in a recess 25. Therighthand end of the spring is adapted to react against the inner endwall 26 of the recess while the other end is biassed against adownwardly projecting key portion 2l and normally urges the key to itsfully projected position in which the depending portion 2l is againstfront wall 28 of the recess. Manual actuation of the switch key isfacilitated by providing on its outer end, one of the push-buttons II,which may be attached thereto in any convenient manner, but, asillustrated in Figure 7, is preferably forced over serrations 29 formedon the outer end 30 of the key.

Referring now to Figures 2 and '1, it is seen that the right-hand innercorner of key 22 is bevelled, as indicated at 3l, and is so positionedas to bear against a similarly but oppositely bevelled edge 32 on one ofa plurality of fingers 33 projecting forwardly from a slide bar 34. Theslide bar is positioned for reciprocatory movement in a transverseguide-way 35, formed in base I4, and extends across the base to a pointslightly past the inner end of switch 2| and into abutting relation witha resilient movable contact element`36 of a switch 31. Transversemovement of the slide bar to the right, as illustrated in Figures 2 and5 will move the end 38 of movable element 36 into contact with thestationary contact element 39 of the switch to thus close an associatecircuit, which, in the present case, controls circuits (not shown) toopen the loud speaker circuit and. thus mute the radio during actuationof the switching mechanism.

A recess 46 is located to the left of switch I6, as seen in Figures 2and '7, and receives a resilient conductor strip 4I which is lockedvwithin said recess by a portion 42 (see Figure '7) extending downwardlyinto a deeper recess 43 (Figure 2) which is oi substantially the samewidth as portion 42, and thus prevents lateral displacement of theconductor relative to the base structure. The innerend of this conductoris provided with a contact loop 44 which extends through an aperture orslot 45 in the side wall 46 of switch key guide-way 23 and-into Contactwith theleft side edge of the keyl A second resilient conductor strip 41is positioned'at the oppositel side of the recess 40 and is lockedtherein by a downwardly extending portion 48 depending into a recess 49of substantially the same width as portion 48. The inner end of thislatter conductor is also provided with a contact loop 50 which extendsthrough anaperture or slot I in the side of wall 46 of guide-way 23 in amanner similar to that already described with reference to contact'loop44 of conductor 4 I.

Switch key 22 has its edge portion cutaway in the region of aperture 5Ithereby preventing contact of the key with loop 50, when the key is inits projected position, and thus maintaining circuit branch IBa -out ofthe Vcircuitucontrolled by switch I6. To close switch I6, pressure isexerted against its push-button II, thus moving key 22 inwardly alongguide-way 23 against the tension of spring 24, until the left sidev edgeof the key (as viewed in Figure 2) contacts loop 53 of conductor 41 andthus closes a circuit including branch I6a, in the manner describedhereinafter. It will be noted that immediately upon inward movement ofthe switch key, toward depressed or operative position, bevelled edge 3Ithereof will move against the bevelled edge 32 of nger 33 to urge slidebar 34 transversely to the right, and thus close muting switch 31 beforeclosing the circuit including branch I6a, as described above. frompush-button II, coil spring 24 immediately returns the key to its normalprojected position and, concurrently therewith, slide bar 34 is returnedto its normal position by the inherent resilience of contact element 36of the muting switch.

Having described the construction and operation of switch I6, whichconditions the mecha- When the pressure is removedl nism for manualoperation by knob I3, the various switches for selecting a particularstation circuit will now be described.

From the drawings, it is seen that each of the remaining switches (I1through 2l) is provided with a switch key 22 similar in every respect tothat just described in connection with switch I6, and that each of thekeys is mounted in a similar guide-way 23. Each key has its bevelledinner end 3l abutting the bevelled end 32 of a corresponding nger 33 onslide bar 34 so that actuation or any one of the keys will move theslide bar to the right, to close muting switch 31 in the mannerdescribed heretofore. In addition to the above-described similarities,each key is similarly held in its projected position by a spring 24positioned; in a recess 25 therebeneath, in the same manner as describedabove with respect to switch I6;

Provided between each pair of switch keys 22 is a recess 524 (Figure 7),each having positioned therein a resilient U-shaped conductor strip 53(Figure 8) having its end portions terminating in contact loops 54 and55 which extend through apertures 56 provided in the walls 51 and 58 ofadjacent guide recesses 23 and into contact with adjacent switch keys.With reference to Figure 4, itis seen that each of these strips isprovided with a portion 59 which depends from its forward end loop 66into a recess 6 i of greater depth than that portion of recess 52immediately beneath the side portions of the strip.

Also positioned inV each of recesses 52 is the inner end 62 of` aresilient conductor strip 63 which, as shown in Figure 4, has itsintermediate portion 64 extending rearwardly and-downwardly through anaperture 65 in base I4, and its outer end 66 terminating. justbeyond-the rear edge of the basemember to provide means for connecting acircuit wire. thereto. The other end portionof this conductor, asillustrated in Figures 4, 5 and '1, is also provided with a laterallyextending. portion 61 terminating in an upwardly extending lamp contactstrip 68, the purpose of which will be described-hereinafter.

The. inner end 62 of this strip comprises a U-shaped member 69, oneendof which comprises a Contact loop 10 which extends through an aperture1I in the` right-,hand wall 58 (as viewed in Figure 2) of each .recess52, while its other side 12 bears vagainst the left-hand wall 51 of therecesses to bias the Vcontact loop 10 in a counterclockwise directionand into contact with switch keys 22 when the Ykey is-in its operativeor depressed position. It willbe noted that in switches i1 through2I-the contact loop 10 of each of conductor strips 63 is in a positioncorresponding to that of contact loop o conductor member 41 relativetothe switch key 22 of switch I6, and that'each ofthe keys has itsleft-side edge cut away, or notched, in the region of contact loop 10 sothat, when the keys are in their normal projected or lrest position, nocontact is made between the loop and the key. Therefore, it can be seenthat, with the particular arrangement of switch keys and hair pinconductor elements, as shown in Figure 2, all of the switch keys are inseries circuit with conductor strip 4i., but, by reason of thenotches,all of the associated circuits are open.v

When it is desired-to close one of the switches, the proper push-buttonis depressed, for example, switch 2D, as shown in Figure, to cause theassociated switch key 22 to bear against contact loop 10` of .conductor63 and/thus to completey a circuit including branch 20a. Each of switchkeys 22 is provided with a recess or notch 'I3 in its right-hand sideedge. When the key is in its projected or rest position, these notcheslie just forward of the plane of the contact loops 55. The purpose ofthis is explained below.

A particular feature of the invention resides in the arrangement of thevarious switch elements just described. It is evident that, when oneswitch key is depressed to select a particular circuit, notch 'I3 movesinto alignment with contact loop 54 of hair pin conductor 53 so that allthe other switches to the right thereof. as seen in Figures 2 and 5, areout of circuit with those to the left. This is illustrated most clearlyin Figure 5, in which it can be seen that the first three of theconductors 53 (counting from the left) are in circuit contact withswitch `keys 22 of switches I8, I9 and 20, but, because notch 13 in theright-hand edge of the switch key of switch 20 has been moved intoalignment with contact loop 54 of the next succeeding or fourth hair pinconductor 53, switch key 22 of switch 2| is out of circuit with theswitch to the right thereof and, therefore, even if switch 2| be pushedin it would not close its associated circuit.

It is apparent, of course, that a similar condition exists with each ofthe other switches upon actuation thereof and that, regardless of whichone is actuated, or whether more than one switch is actuated at onetime, only one switch can possibly be operative to close the circuitcontrolled thereby; the controlling switch of those actuated being theone closest to conductor strip 4|. Thus, for example, and with referenceto Figure 2, it can be seen that, if switch should be actuated, all ofthe switches to the lright thereof are out of circuit contact therewithand operationof any one, or more, would be ineffective to close anothercircuit.

Mechanism is provided for indicating, by i1- lumination on the face ofthe dial 14 of bezel I5 (see Figure l), the particular circuit orstation in operation. With reference to Figures 2, 3, 5 and '7, it canbe seen that this mechanism comprises a part of the switch mechanism andincludes a plurality of lamps 16, one for each of switches II through2|, mounted in recesses l1, of which the lower half 'I8 is formed inbase I4 adjacent the rear edge 'I9 thereof, while the upper half 80 isformed in a cover member 8l secured to the base in any suitable manner,as, for example, by screws 82. One of the contacts for energizing thelamps is provided by the upstandin'g end portion 68 of conducting strip63 which, as shown, abuts the rear contact element 83 of the lamp. Theother contact is provided by a strip 84 secured to the rear edge 19 ofbase I4 (see Figure 6). With reference to Figure 4, it is seen that thisstrip is provided at intervals, along its top and bottom edges, withclamping elements 85 and 86, respectively, which are adapted to t intotop and bottom recessed portions 87 and 88, respectively, of base I4, tohold the strip firmly to the rear edge thereof. The strip is alsoprovided at its right-hand with a tab 89 for connecting it with one sideof the lamp circuit and, at intervals corresponding to the space betweenthe bases of the lamps, with loops 90 in which the side wall contactstuds 9| of the lamps are engaged. Energization of the lamps is by anysuitable means in circuit with each of the corresponding push-buttons,so that actuation of any one of the push-buttons Will also energize theassociated lamp, for example, see the lamp circuits illustrated inFigure 9. In this ligure the lamp shown associated with circuit Ia isadapted to illuminate dial 'I4 during manual tuning by knob I3.

In accordance with a further feature of the invention, means is providedto conduct the light forwardly to indicate on the dial the stationselected. This is accomplished by providing a light conducting element92 which may comprise any suitable substance, such as one of the clearplastics of the methyl-methacrylate family, of which the lightconducting characteristics are well known. Each of these lightconducting elements comprises a flat elongate strip portion 93positioned in a groove or recess 94 in the under, plane surface 95 ofbase I4, as illustrated in Figure 3, but which is, in actuality, the topsurface of the present embodiment, when assembled in the housing I0.This position is, of course, a matter of choice, it being understoodthat the mechanism may assume any convenient position permitting manualactuation of the push-buttons.

As seen in Figure 3, the groove 94 extends from the lower front edge 96of the base to a position beneath the lamp-receiving aperture andterminates in an enlarged portion 91 extending upwardly into lamp recessTI. An inner end portion 98 of light conducting element 92 extendsupwardly into and substantially fills aperture 91, and the innermost end99 is so positioned as to receive light from the lamp, which light isconducted forwardly through the strip portion 93 and directed upon thedial 'I4 immediately above the particular push-button actuated (seeshaded area above switch 2D in Figure 1). A cover plate I9!) is securedover the surface 95 to prevent displacement of the light directingelements from grooves 94.

With reference to Figure 7, another of the primary advantages of theinvention becomes apparent. This view illustrates the simplicity ofassembly of this switch, it being necessary merely to drop most of theparts in the particular recess or aperture adapted to receive them.

It should be understood that the normal condition of each of theresilient conductor elements is preferably somewhat extended incomparison to its condition when disposed within base I4. See, forexample, Figure 8, which shows one of the hair pin conductors 53 in itsnormal condition when removed from the base member I4. As seen in thisgure, the side walls are spread outwardly at an angle greater than theangie therebetween when the element is in its recess. Therefore, when itis stated in the following description that the various resilientconnectors are dropped into their recesses, it is to be understood thatthey are rst flexed to the condition in which they are shown in Figure2. f

In the process of assembling the various elements of the switch inproper position in base I4, spring 24 is dropped into recess 25 afterwhich switch key 22 is dropped into its guide recess 23 with itsdownwardly extending portion 2l between the front wall 28 of the recessand the outer end of the spring; the connectors 4| and 41 are droppedinto the recess 40, and slide bar 34 into its guide recess 35. Conductorstrip 63 is assembled with the base by passing its inner end 62 upwardlythrough aperture 65 into recess 52, as shown, and then lifting its outerend 66 upwardly over a stud IDI, depending from and preferably integralwith base I4, a hole I Illa being provided for that purpose. After thisa speed nut |02 is secured over the stud to hold the strip securely inplace. When these various physical components of the mechanism have beenassembled as described, a cover plate |03 is secured over theseelements, as by screws |04, to prevent displacement of the variouselements.

A's above2indicated, the circuit selecting apparatus of the inventionhas been illustrated, in Figure 9, in association with an exemplarycircuit adapted to be controlled by su'ch apparatus', while-insofar asthe concepts of the present inventi'on are concerned-other circuits maybe employed, reference to the showings 'of Figure 9 provides a properbasis for an exposition of the complete operational sequence.

In general, the arrangement of Figure 9 comprises, inter alia, aschematic representation of the switch device hereinbefore described, abattery |09 (for example, a 'ii-volt storage battery, if the apparatusis 'employed in an automobile), a rotary switch having a rear section H9and a front section |20, suitable pretuned' station-'selecting circuits|2|, and an actuating solenoid I |4 which, when energized from thestorage battery |09, is effective to step or rotate the rotary switchfrom a given switch position to a succeeding position. The front andrear sections of the rotary Switch, the actuating solenoid, and thepretuned station-selector device l2| are. mechanically ganged byconventional means (illustrated diagrammatically by the broken lineV I3)so that upon each operation of the actuating solenoid H4 thestation-selector device |2| is switched from one position, in which apredetermined station is received, to another position in which adifferent station is received. Such station-selectin'g arrangements arewell-known in the art and it is unnecessary here to describe this devicein additional detail.

The actuating solenoid |`|4 is of a type, well known in the art, which,when energized, functions to effect a step-by-step rotation of therotary switch. In the arrangement illustrated there are three switchpoints per quadrant, and the solenoid is adapted to step'the rotaryswitch through a sector of 30 Der sten.

The circuit condition illustrated in Figure 9 is that vobtaining as theresult of a prior actuation of switch 2|. This, as will be understoodhereinafter, can be determined from the fact that top gap H8 in theiront section of the rotary switch is opposite the contacter associatedwith branch or conductor 2|a which, in turn, is associated with switch2|. The mode of operation ofA the circuit in response to the actuationof any 'of the push-buttons will be readily understood by trfacing theactions resulting from a depression of` a specic push-button, forexample, that associated with the switch 20. When switch 20 is depresseda connection is effected between the contact elements 55 and 'l0associated with the said switch 20. This completes the actuatingsolenoid circuit, which circuit comprises4 the grounded negativeterminal of the battery, switch-key grounding conductor 4|, switch-keysand key interconnectors 53, contact elements 55 and 10 associated withselector switch 20, conductor a, the rotary switch contactor (HT)associated with the conductor 20a, front section of the rotary switch,conductor H2, commutating switch |3, and finally the upper terminal ofthe actuating solenoid H4. As soon a's the circuit is completed throughthe solenoid H4, as above outlined, the actuating solenoid is'energzed'and functions, in known manner, to step or advance the rotaryswitch, clockwise, through an angle of 30. This stepping action of theactuating solenoid will be continued step-bystep, until theabove-'described circuit is broken. In thepres'e'nt instance the circuitis broken immediatelyup'on the rst 30 rotation of the 1'0- t'ar'yswitch, for in that position the gap H8 in the front section of theswitch falls beneath the contacting element associated with theconductor 20a. Upon the return of the selector Switch 20 to its restposition (shown) the indicator lamp H5 is energized and serves toidentify the selected station. The circuit which results in theillumination of the lamp corresponding to the station-selector switch 20may be traced as follows: the upper terminal of the selected lamp isconnected directly to ground through the agency of the rear section H9of the rotary switch which, through the action previously outlined, hasbeen turned to a position 30 clockwise from that illustrated. The lowerterminal of the lamp is connected through 'all of the remaining lampsand throughkthe conductors |G`a, Ha, |80., |`9a and 2|a to the frontsection |20 of the rotary switch and thence through the conductor H2,con'unutat'or switch H3, and the solenoid H4 to the positive terminal ofthe battery |09. It will oe observed that the current which energizesthe lamp shown at H5 divides equally between the other iive remaininglamps, the current in the latter lamps being insuflicient to effectincandescence therein. It is to be noted that none of the lampsis'illuniinated during the period of rotation of thel rotary switch. Theillumination from lamp H5 is, of course, conducted to the region of thedial in the manner described hereinabove.

I claim:

l'. In a switching device, an insulating base member provided with aplurality of recesses, a plurality of conducting keys each disposed in acorresponding one of said recesses and movable therein between operativeand rest positions, a plurality of conductor elements each disposed inothers of said recesses and normally making contact with said keys andconnecting the same in series circuit relation, and a plurality ofcontacts supported by said base member and each associated with acorresponding one of said keys and normally spaced therefrom, each keybeing engageable with its associated contact in response to movement ofthe key to operative position, whereby to provide for closing of acircuit which includes the contact engaged by the key and at leastcertain of said conductor elements.

2. In a switching device, an insulating base member provided with aplurality of recesses, a plurality of conducting keys each disposed in acorresponding one of said recesses and movable therein between operativeand rest positions, a plurality of conductor elements each disposed inothers of said recesses and normally making l contact with said keys andconnecting the same in series circuit relation, said keys and conductorelements being individual members readily insertable in and withdrawablefrom said recesses whereby to facilitate assembly and disassembly ofsaid switching device, a plurality of contacts supported by said basemember and each associated lwith a 'corresponding one of said keys andnormally spaced therefrom, each key being engageable with itsassociatedl contact in response to movement ofthe key to operativeposition whereby to provide frclosing of acircuit which includesthcontact engaged by the key and at least certain of said conductorelements, and cover means effective to retain said keys and conductorelements in assembled relation.

3. In a switching device, an insulating` base member provided with aplurality of recesses, a plurality of conducting keys each disposed in acorresponding one of said recesses and movable therein between operativeand rest positions, and a plurality of conductor elements each disposedin others of said recesses and normally making contact with said keysand connecting the same in series circuit relation, said keys andconductor elements being individual members readily insertable in andwithdrawable from said recesses whereby to facilitate assembly anddisassembly of said switching device.

4. In a switching device, an insulating base member having surfaceportions provided with a plurality ofy outwardly-facing recesses, aplurality of conducting keys each disposed in a corresponding one ofsaid recesses and movable therein between operative and rest positions,a plurality of conductor elements each vdisposed in others of saidrecesses and normally making contact with said keys and connecting thesame in series circuit relation, said keys and conductor elements beingindividual members readily insertable in and withdrawable from saidrecesses whereby to facilitate assembly and dis assembly of saidswitching device, and cover means disposed across the surface of saidbase member and effective to retain said keys and conductor elements inassembled relation within said recesses.

5. In a switching device, an insulating base member provided with aplurality of recesses, a plurality of conducting keys each disposed in acorresponding one of said recesses and movable therein between operativeand'rest positions, a plurality of conductor elements each disposed inothers of said recesses and normally making contact with said keys andconnecting the same in series circuit relation, said keys and conductorelements being individual members read-ily insertable in andwithdrawable from said recesses whereby to facilitate assembly anddisassemblyl of said switching device, a plurality of contacts supportedby said base member and each associated with a corresponding one of saidkeys and normally spaced therefrom, each key being engageable with itsassociated contact in response to movement of the key to operativeposition, and cover means effective to retain said keys and conductorelements in assembled relation, at least certain of said keys beingprovided with a notched portion so disposed that movement of a key tooperative position breaks contact between the moved key and an adjacentconductor element.

6. In a switching device, an insulating base member provided with aplurality of recesses, a

plurality of conducting keys each disposed in a corresponding one ofsaid recesses and movable therein between operative and rest positions,a plurality of conductor elements each disposed in others of saidrecesses and normally making contact with said keys and connecting thesame in series circuit relation, said keys and conductor elements beingindividual members readily insertable in and withdrawable from saidrecesses whereby to facilitate assembly and disassembly of saidswitching device, a plurality of contacts supported by said base memberand each associated with a corresponding one of said keys and normallyspaced therefrom, each key being engageable with its associated contactin response to movement of the key to operative position, and aplurality of lamps each disposed within still others of said recessesand each associated with a corresponding one of said keys and adapted tobe illuminated in response to movement of the corresponding key tooperative position.

7. A construction in accordance with claim 6, and further including aplurality of light-conducting members supported upon said base member incooperative light-conducting relation with respect to said lamps, saidlight-conducting members extending to a predetermined visible region ofsaid base member, whereby to provide indicating illumination in saidregion.

GILBERT J. KENNEDY.

-REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Abstract, 691,280, O. G. May 9,1950, p. 646.

